Cured silicone powders are used as additives, for example, for cosmetics, paints, inks, thermosetting organic resins, and thermoplastic organic resins, and are particularly well suited for use as internal stress-relaxing agents for thermosetting organic resins and as surface lubricants for organic resin films. However, these cured silicone powders are strongly aggregative and as a consequence exhibit a poor flowability; moreover, they are poorly dispersible in water-based compositions such as water-based paints and cosmetics. When as a result the cured silicone powder does not undergo uniform dispersion in a water-based composition and occurs in an aggregated state in the water-based composition, a uniform matting effect will then not be generated by the cured silicone powder in the case of water-based paints, while a poor tactile sensation is obtained in the case of cosmetics.
Improved-flowability composite cured silicone powders comprising an inorganic fine powder coated on the surface of a cured silicone powder have been introduced (refer to JP 04-348143 A, JP 07-102075 A, and JP 09-208709 A). However, these composite cured silicone powders have a poor hydrophilicity, and when incorporated into a water-based composition exhibit a poor affinity for the water-based composition.
A composite cured silicone powder having an increased hydrophilicity achieved by attaching a surfactant on the fine inorganic powder has also been introduced (refer to WO 2004/055099). However, to maintain a satisfactory hydrophilicity the surfactant must be attached in large amounts in the case of this composite cured silicone powder, and this has made compositional design of water-based cosmetics quite difficult.
[Patent Reference 1] JP 04-348143 A
[Patent Reference 2] JP 07-102075 A
[Patent Reference 3] JP 09-208709 A
[Patent Reference 4] WO 2004/055099